Are luxury hybrids as green as you think?

The newest auto trend is upscale cars with hybrid badges. They have high price tags and plenty of power. But do they really save you money on gas?The new BMW hybrid has over 400 horsepower and can blast to 60 mph in under four seconds. You can own one of these luxury vehicles for $90,000.

The new Active Hybrid X6 is the latest in an increasing number of luxurious, powerful hybrid cars with high price tags. Hybrids aren't just thrifty economy cars these days.

Lexus actually started the high-end hybrid trend, which was fairly easy since parent company Toyota got a big start in hybrid technology.

The GS Hybrid sports sedan costs about $60,000. The large LS 600 is like a hybrid limo with a price tag well into six figures.

Mercedes has entered the luxury hybrid game too with a gas-electric S Class sedan.

All these cars save some amount of fuel, but they have something else going for them too -- environmental bragging rights for their owners.

"When you are talking about the luxury market you are already getting that standard and then you are getting that other badge on your chest," said Bell.

Some environmentalists criticize these luxury hybrids for not being all that "green." It is true that they do not get the high mileage like a Prius does, but they do get better fuel economy than the non-hybrid versions of the same cars.

In the case of the Lexus and BMW models, they can travel at low speeds on electric power alone. The Lexus LS even has an EV Mode that keeps it purely electric at low speeds.

The trend of luxury hybrids is still growing. BMW is also launching a hybrid 7-Series to compete with the big Lexus in both size and price. And hybrid Porsches are on the way too.

It's a new world for hybrid vehicles: technology, performance and luxury all-in-one, with some improvement in gas mileage too.